RU96116907A - METHOD FOR CONTROL OF URANIUM ENRICHMENT IN POWDERS UO * 002 - Google Patents

Claims (1)

A method for controlling enrichment in UO ₂ powders, including measuring the gamma-ray spectrum of a sample with a characteristic size that ensures self-absorption of gamma-radiation in the range 0 - 300 KeV using a scintillation detector spectrometer, and subsequent processing of the spectrum by calculation, characterized in that they interpolate spectrum and step-by-step integration so that the maximum of the main analytical peak falls into a given channel containing 186 keV energy; then, the spectrum is digitally filtered with individual peaks of gamma radiation U ²³⁵ and thorium isotopes, as well as x-ray radiation of total uranium, measure the areas of the selected peaks, normalize the areas of all these peaks by dividing by the area of the main analytical peak to obtain normalized intensities I _Th231 , I _Th234 , I _XRay , determine the auxiliary the parameter r from the formula r = (1 + pI _Th231 + q I _Th234 ) / I _XRay , and then the sample enrichment is determined by substituting r in the calibration dependence between the enrichment and r values, which, together with the parameters p and q, is determined by tuning ke instrument from solving a system of equations
r _j I $\genfrac{}{}{0ex}{}{\text{ij}}{\text{Xray}}$ - pI $\genfrac{}{}{0ex}{}{\text{ij}}{\text{Th231}}$ - qI $\genfrac{}{}{0ex}{}{\text{ij}}{\text{Th234}}$ = 1,
where j is the number of the relaxing training sample;
i is the number of measurements taken on this sample during the establishment of radiation equilibrium,
calibration is carried out by comparing the values of r _j and the enrichment values independently determined by laboratory methods in relaxing training samples.